/*! ******************************************************************************
 *
 * Created on 2022年3月28日
 *
 * Copyright(c) YuZhou Big Data Laboratory CO.,Ltd, 2022.  All rights reserved.
 *
 *******************************************************************************
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 ******************************************************************************/

package org.yzbdl.lanius.core.metastore;

import java.util.List;
import java.util.Map;

import com.google.common.collect.Lists;
import com.google.common.collect.Maps;

/**
 * @author hs@yzbdl.ac.cn
 *
 */
public class SqlBuilder {

    private List<Map<String, BaseEntity>> entityList = Lists.newArrayList();

    private SqlBuilder() {
        super();
    }

    public static SqlBuilder from(BaseEntity entity) {
        SqlBuilder sqlBuilder = new SqlBuilder();
        return sqlBuilder.push("from", entity);
    }

    public SqlBuilder leftJoin(BaseEntity entity) {
        return this.push("left join", entity);
    }

    public SqlBuilder rightJoin(BaseEntity entity) {
        return this.push("right join", entity);
    }

    private SqlBuilder push(String oper, BaseEntity entity) {
        Map<String, BaseEntity> map = Maps.newHashMap();
        map.put(oper, entity);
        entityList.add(map);
        return this;
    }

    public String build() {

        return this.toString();
    }

}
